I am reviewing the Cubbyhole and the response-wrapped token concept and I’m confused.
From what I understand, I can create a token that allows 2 uses and has a time limit. With that token, I can write a secret to the Cubbyhole, send the token to someone else, and they can either access the token (and no one else can as that is 2 uses), or they cannot access the token if someone has already read it.
Or, I can use the sys/wrapping/wrap endpoint to wrap up the token used to put the data in the Cubbyhole and send the response-wrapped token to someone else. Again, they can either unwrap the token and access the secret in the Cubbyhole, or they cannot.
In both cases, I can view the audit logs to see who attempted to use the token, or unwrap it.
Why would I use the response-wrapped token? Is it just because the added step of unwrapping a token slows down bad actors a smidgeon?
The use cases you describe are roughly equivalent, but I think the utility of token wrapping is much broader than you’ve outlined: you could wrap a periodic token that never expires, for example.
In theory, you could imagine a scenario where you extend access to your environment for all your existing use cases, without breaking your existing security policy, simply by introducing token wrapping. In practice, you’d obviously want to conduct a new risk assessment prior to introducing such a fundamental change, and strengthen your processes, around monitoring and auditing as a minimum, I’d imagine.
Hi Lyndsey! Sure, but first, it’s important to note that, even in the case of a long-lived periodic token, you wouldn’t want the TTL of the response-wrapping token to match it; this is one of the key benefits of response-wrapping, as outlined in HashiCorp’s documentation: regardless of the secret/token being wrapped, you can limit its lifetime in the event that it doesn’t reach its intended recipient.
So, as an example, I could create a periodic token for use as part of my automated Consul gossip key rotation, with the limited privilege of being able to read a secret from a specified path. As designed, this token should be used by consul-template to read the encryption key from Vault, and, if it’s changed, to add that key to Consul’s keyring, and remove all the old ones.
If my risk assessment suggested that passing that periodic token over the wire might put it at risk of interception, I would probably just configure TLS between all my nodes. But you can imagine a scenario where it might not be practical to have verifiable certificates at all endpoints. Response-wrapping that periodic token could be one solution, providing it cover (and tamper detection).
This is actually a point where your two-use token would not provide the same utility: there’s only one TTL associated with it, whereas, I could put a TTL of an hour on my periodic token, and then, regardless of how long it’s supposed to be valid, if consul-template doesn’t unwrap it and use it within an hour, it would expire.